https://h30306.github.io/blog/tags/dp-on-trees/Recent content in Dp-on-Trees onHugo -- gohugo.ioenhwork0511@gmail.com (Wei Yi Chung)hwork0511@gmail.com (Wei Yi Chung)© 2026 Wei Yi ChungSat, 31 Oct 2026 00:00:00 +0000https://h30306.github.io/blog/leetcode/leetcode-834/Sat, 31 Oct 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-834/LeetCode 834 note: rerooting DP: compute subtree sizes and ans[0] with root 0, then push ans[child] = ans[parent] - size + (n - size) to every nodehttps://h30306.github.io/blog/leetcode/leetcode-968/Fri, 30 Oct 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-968/LeetCode 968 note: post-order greedy with three states per node: has a camera, covered, not covered; place a camera only when a child is uncovered, and add one if the root is left uncoveredhttps://h30306.github.io/blog/leetcode/leetcode-124/Sat, 24 Oct 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-124/LeetCode 124 note: DFS returns the best downward chain and updates the answer with left chain + node + right chain at every node; drop negative chainshttps://h30306.github.io/blog/leetcode/leetcode-1372/Sat, 24 Oct 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-1372/LeetCode 1372 note: each node returns two values, the longest zigzag starting left and starting right; going left extends the left child’s start-right valuehttps://h30306.github.io/blog/leetcode/leetcode-687/Sat, 24 Oct 2026 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-687/LeetCode 687 note: DFS returns the longest same-value downward chain in edges, and each node updates the answer with left + righthttps://h30306.github.io/blog/leetcode/leetcode-563/Sat, 27 Aug 2022 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-563/LeetCode 563 note: return subtree sums in post-order; each node’s tilt is the difference of its subtree sums, added to the answerhttps://h30306.github.io/blog/leetcode/leetcode-543/Thu, 25 Aug 2022 00:00:00 +0000hwork0511@gmail.com (Wei Yi Chung)https://h30306.github.io/blog/leetcode/leetcode-543/LeetCode 543 note: the diameter may skip the root; return heights in post-order while updating the answer with left + right height at every node, counting edges